remove git add for lint-staged hook (#5911)

package.json

@@ -46,8 +46,7 @@
   "lint-staged": {
     "**/*.less": "stylelint --syntax less",
     "**/*.{js,jsx,tsx,ts,less,md,json}": [
-      "prettier --write",
-      "git add"
+      "prettier --write"
     ],
     "**/*.{js,jsx,ts,tsx}": "npm run lint-staged:js"
   },